
Hi Sharon.
Does this happen at night? If so, is there anything you could think of that's different at nighttime, that could be stressful for her? Is she left alone with her pups during the night/day? Could it be she feels insecure, wanting the support you could give her?
Can she choose to get away from the pups for a while, if she wants to? Even doggy-mums need some time to themselves ;-) . At four weeks she can't be expected to clean up after her pups. Some bitches keep doing it, even after the pups are weaned, some don't. Is it a big litter? Are her teats alright? No sores or blisters?
Is she still having discharge? If so, what's it like? Some bitches can keep bleeding for a prolonged time, due to slow healing in the places where the placentas have been attached. This can be an added strain in combination with producing milk, making her worn out.
Have you got other dogs in the house? If so, is she protective or will she let them help in rearing the litter?
I'm sure someone else will come along in the morning, with more suggestions. As long as you are sure she's not having an ongoing infection, or other health issues, maybe these things could be worth thinking about, as a start?
Good luck! At four weeks pups are just adorable :-) . My favourite age!
All the best,
Karen